Common vole in Spain

common vole: topillo campesino: Microtus arvalis

Common voles were the environmental story of summer 2007 when as many as 750 million spread across an area of two million hectares in Castilla y León. Agriculture was severely hit: some 500,000 ha of crops were devastated with losses of 15 million euros, as the voles munched their way through Spain’s breadbasket, earning them the epitaph of the scourge of Castilla. Moreover, more than one hundred people caught tularaemia (rabbit fever) from handling the voles or touching contaminated soil.

The tendency of vole populations to fluctuate widely was exacerbated by farming practices. Until 20 years ago, the common vole was only found higher up in the meadows of the Pyrenees, Picos de Europa and the Sistema Central. It seems that agricultural changes in the cereal steppes from dry farming to irrigated crops have encouraged the voles to expand into the cereal plains where natural predators have been decimated by hunting and poison. A barrage of methods were tried including  scorching burrows and stubble with flamethrowers and the mass use of poison, but in the end the vole population dropped back to normal levels, more than anything due to natural control mechanisms of the vole themselves.

  • Pages